Objective    To investigate the effects of Exendin-4 on islet β-cell function and glucose-lipid metabolism in obese rats induced by high fat diet.     Methods    Forty Sprague-Dawley (SD) rats were randomly divided into NC group (fed with normal chow diet

n=10) and HF group (fed high fat diet for 10 weeks

n=30). The rats in HF group were subdivided into three groups according to the single dose of Exendin-4 (0

0.5

2 μg/kg) that was intraperitoneally injected twice a day for 6 weeks. The islet β-cell function

insulin sensitivity and glucose lipid metabolism in awake rats were evaluated by intravenous glucose tolerance test (IVGTT) and insulin tolerance test (ITT).     Results    Lee’s indexes

blood glucose (BG)

plasma free fatty acids (FFA)

triglyceride (TG) and total cholesterol (TC) levels were significantly increased in high fat diet rats

but they were significantly decreased after Exendin-4 treatment (all P0.01). In these obese rats

Exendin-4 treatment achieved better results of IVGTT and ITT (P0.05)

also better islet β-cell function (P0.05)

and increased insulin secretion (P0.01)

especially when a high dose of Exendin-4 was administered.     Conclusion    Exendin-4 treatment ameliorates islet β-cell function and improves glucose-lipid metabolism in obese rats induced by high fat diet

seemingly in a dose-dependent manner.